plotter

What do you do when you have an old printer, a portable CD player, and a handful of other electronics sitting around? Turn it into a plotter, of course.

The frame of the plotter was taken from a ye olde Epson printer, reusing the two stepper motors to move the paper along its length and width. The pen is attached to the laser head of a junked portable CD player. With this, it’s just three stepper motors that allow the Arduino control system to move the pen across the paper and put a few markings down.

The motors on the printer are, in the spirit of reuse, still connected to the printer’s driver board, with a few leads going directly from the Arduino to the parallel port interface. The motor in the CD player is another ordeal, with a single H-bridge controlling the lifting of the pen.

On the software side of things, a Processing sketch reads an SVG file and generates a list of coordinates along a path. The precision of the coordinates is set as a variable, but from the video of the plotter below, this plotter has at least as much resolution as the tip of the pen.

The years went by, dust accumulated, and in 2010 [Vegipete] found himself doing some work with linear acceleration on a PIC microcontroller. Remembering his old plotter, [Vegi] realized he could build an embedded version of his old Apple ][ circuit. He built a circuit that turned the plotter into something that can be controlled with an FTDI adapter. A small update to the code added the an Easter egg. When the Konami code is entered on the plotter’s buttons it responds in the spirit of our Fubarino contest.

[Jack Boland], a mechanical engineer at the University of Wisconsin, built a cool hanging plotter project called HangBot. It’s a fairly standard setup, where he converts an image to G-Code files, and it is plotted using two stepper motors for control. We’ve seen vertical plotters before, but they tend to only have a single pen. [Jack] expanded this one to bring color into the mix by splitting an image into separate CMYK layers, and plotting each onto separate transparency film. When overlaid, they create something close to a full color image. His idea is to use this setup as a replacement for typical window signage.

Since it’s drawing a continuous line, he appears to be employing a grid instead of a traditional dot pattern. That, combined with the inaccuracy of a marker tip means resolution will be limited. Still, you can tell that he’s made a great start in this (albeit blurry) photo. Check out the video of it’s operation after the break.

[Ben], [David], [Drew], [Kayla], and [Peter] built a robotic artist as their senior design project. This mashes up a bunch of different project ideas, but the thing we like the most about it is that it works much like a photo booth that produces a painting. A Raspberry Pi uses a webcam to snap the picture, converts the image to three colors (plus the white background of the canvas) and sets the robot in motion. The team laments that initial testing of the completed project (seen in the clip below) worked out quite well but took hours to produce the painting. What do they expect? It’s art!

This is quite a bit different from the WaterColorBot (whose manufacturing process we just looked in on yesterday). WaterColorBot uses a flat canvas and a gantry system. This offering, which is called PICASSAU, uses an upright canvas with the paintbrush mounted in much the same way as a plotter robot. The biggest difference is that there is the ability to pivot the paint brush in order to pick up more paint, and for cleaning in between color changes.

[Jay]’s plotter is based on the Piccolo, an exceedingly small-scale CNC platform that can be built for $70 with laser-cut parts. This version, though, uses only six parts that can be downloaded from Thingiverse. Powered by an Arduino and two micro servos, this CNC plotter would be a great introduction to CNC for any robotics club or hackerspace tutorial series.

Here’s an Android powered pen plotter that does it all. It was built by [Ytai Ben-Tsvi] to take with him to Maker Faire. He’s the creator of IOIO, a hardware interface module designed to communicate with an Android device via USB (host or OTG are both supported).

The physical hardware is simple enough. He draws on a pad of white paper using a felt-tipped marker. Located at the top of the easel are two wheels with stars etched on them. They are reels which spool and dole-out string to control the pen’s movements. The pen tip can be lifted by a ball bearing mounted just below it.

But the project really takes off when you watch [Ytai’s] demonstration. The Android tablet controlling the device captures a picture of an object — in this case it’s a toy truck. The app then processes it using edge detection to establish how to plot the image.

Check out this robot arm capable of handwriting which is orders of magnitude clearer than our own. It was built by [Patrick Barnes] as contract work for a campaign to raise funding for research into Duchenne Muscular Dystrophy.

Don’t miss the video after the break which starts off with the satisfying whine of some serious stepper motors. Judging scale from this image is a bit tough, but [Patrick] tells us that the entire assembly stands almost fourteen inches tall and the arm has a reach of around twenty inches. The demonstration shows off it’s abilities by drawing a Hilbert Curve. From watching the action you’ll realize that, though this arm and hand look fantastic, this is really a SCARA plotter. The wrist and fingers are for looks only, providing a place where the felt-tipped pen can be mounted (held flush to the paper with a rubber band). Whether that’s a disappointment or not, the precision and look of the machine bring it very high marks. It could take a bit of a lesson in penmanship from another we’ve seen though.